Preheat oven to 350 degrees. Peel the onion, leaving the rootstrimmed but intact. Cut in 1/4-inch slices from stem to root, butdon't cut through the root end. Turn each onion at right anglesand cut again so that when you stand it on its root end, it willform a flower design.

Oil a baking dish lightly. Salt the onions and place them on theirroot ends in baking dish. Sprinkle vinegar over each onion anddribble butter over them until well coated. Cover lightly withfoil and bake for 1 to 1 1/2 hours, basting several times. Add afew chopped pecans to the center of each onion and continue bakingtogether 1/2 hour.

Remove from oven; season with salt and pepper, and sprinkle withchopped parsley. Serve hot or at room temperature.